Photographic material containing dialkylaminobenzylidene filter dye



Jan. 16, 1951 G. H. KEYES ET AL 2,538,009

PHOTOGRAPHIC MATERIAL CONTAINING DIALKYLAMINOBENZYLIDENE FILTER DYE Filed Sept. 24, 1949 /qyer conza/'m'q cago/er w/v/c forms maya/va aye.

Sup/Dor ATTORNEYS Patented Jan. 16, 1951 PHOTOGRAPHE() MATERIAL CONTAINING DIALKYLAWHNBENZYLIDENE FILTER DYE Grafton H. .Keyes Arthur H. Herz, and `Leslie UNITED STATES PATENT OFFICE G. S. Brooker, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, `N. Y., a corporation of New Jersey Application September 24, 1949, Serial No. 117,710

process. A further object is to provide a process for preparing such photographic materials. @ther objects Will become apparent hereinafter.

In accordance with our invention, We prepare Preparati-OH f fllel layers in DhOtOgahiC 61- 5 photographic silver lhalide materials containing ments. `l-i'ovfever, but a relatively few of these `one or more of the dyes represeiitedby Formula dyes are completely satisfactory, because the dyes lV above. These dyes can bedispersed in a Suitare not completely Vand permanently bleached able colloid, e. g. geatin, gum arabic, casein, the during the developing process. In many cases, calcium salt of polyglycuronic acid, fete., and the there remains Aa `more or less strong coloration, or dispersion employedas` a separateiilter layer to the coloration reappears, or is strengthened durprevent substantially the transmission of blue ing the subsequent drying. light. Such a separate `filter laye'r can be coated Examples of dyes which do not bleach comon top of a single emulsion layer or can be posipletely during the developing process are th-ose tioned `.between two or more emulsion layers. dialkylaminobenzylidene dyes which can be rep- The dispersion can also be mixed with and made resented by the following general formula: an integral part of an emulsion layer. The dyes I `R1 of Formula IV wherein n represents one are es- R N ,CH N/ pecially in connection with filter layers employed in color photographic materials.

R2 20 Dispersions of the aforesaiddyes of Formula IV H R1 can also be employed `as `an antihalation bacliing for photographic materials containing silver R N=CHCH=CHN\ halide emulsions which are not spectrally (opti- Pa cally sensitized) orlas an overcoat for correcting and color balancelof photographic color iilni. m o CN R The dyes of Formula IV above which are esl 1 pecially useful can be represented by the follow- R0` C=CH-C N\ ing general formula:

R2 O ClN /Rx wherein R1 and R2 each represents an alkyl group 30 Ra-CHJ-C=CH(CH=CH)n-i-N and R represents any monovalent organic radi- \.ii2 cal.

We have HOW found that dalkylammobenzyli wherein R1 and R2 have the values given above dene dyes which can be represented by the oll and R3 Tepreents an alyl group of the benzene lowing general formula: series containing in addition to carbon atoms .no

atoms other than hydrogen, oxygen, sulfonamido IV (l) TN /Rl sulfur atoms, sulfonamido nitrogen atoms, and R3-t1-C=oH(-CH==CH)-1DN carboxaniide nitrogen atoms. In all cases the B2 R1 and R2 groups are advantageously primary 4o alkyl groups of the formula CmH2m+1 wherein m wherein D represents a n-arvlene group of the represents a pcsitive-intever cf'from 1 to 4, i. e. benzene series7 Rr and .Re each represents an alkyl methyl, eti/w1, `n pwpyl, isobutyl and 11-buty1 slup, and Re lelJleSSIlS 2m aryl SYOUP 0f 1311 The R3 group advantageously contains one or jllel'l' SllES, 131621811 readily When phOtOgI'phlC more hydroxyl groups, one or ynore Calboxyalkyl materials comprising the dyes are processed in groups,e.g. carboxymethyl, one or more carboxy- SGMNL'UDS COltDDg sulfites. acylamino groups, e. g. --carboxypropionamido,

iS, ElCCOldlgy, M1 Obje? 0f 011.1" IIVSHGOR carboxybenzarnido, arboxyacrylamido, y-car to provide photographic materials provided with boxybutyramido, etc. The R3 group can contain fter dyes which are completely and permanently acylamno groups, e. acetami-do, ,propionaniida bleached during the photographic developing, 5l) isobutyramido, etc; alkylsulfonarndo groups, e. g.

methylsul'fonamido, ethylsulfonamido, n-propylsulfonamido, n-butylsulionamido; or arylsulfonamido groups, e. g. phenylsulicnamido, ptolylsulfonamido, etc.

The following examples will further demonstrate the practice of our invention.

Example 1 50 g. of a-[p-(,B-carboxypropionamido)ben- Zoyll a (pdi-npropylaminobenzylidene)acetonitrile having the formula:

i iN

CHQ-CHT-CHg were dissolved in one liter of water containing g. of sodium hydroxide. This solution was added slowly, with stirring, to a dispersion of one pound of gelatin in 9 lbs. of water, at 40 C. immediately after the addition of the dye, 4.3 liters of a 1% (by weight) Water solution of lead acetate, Pb OOCCH3)2.3E-I2O, were added to the dye gel, with vigorous stirring. The gel was then chilled until rigid, shredded and washed in cold running water, until no lead suliide could be detected in the wash water upon testing with sodium sulfide. With the wash completed, the rigid gelatin dispersion was remelted and made up to 30 lbs. Weight with water. The resulting dispersion when coated over an area of 1000 sq. it. either on top of one or between two or more emulsion layers, will transmit not more than 1% of the incident light of Wavelength 450 ma.

In general a coating of the above concentration can be used as a separate lter layer to prevent the blue-red and blue-green sensitive layers of a multi-layer color photographic material from ex- GHz-CHi-CHa photographic silver halide emulsion used for black and white photography, e. g. aerial photography.

A gelatin dispersion of the dye given in Example 1 above can be employed as an antihalation backing for a photographic silver halide emulsion which is not dye-sensitized.

A gelatin dispersion oi the dye of Example 1 can also be employed as an overcoat for correcting color balance of photographic color iilm. When used for this purpose or when employed as an antihalation layer, the concentration of the in the overcoat or antihalation layer can ordinarily be smaller than the concentration given in Example l above, e. g. one-half, one-third, one-tenth or even one-twentieth of the above concentration.

Example 2 26.5 g. of ap-di-n-propylaminobenzylidene)- a (p phenylsulfonamidobenzoyl)acetonitrile which has the following formula:

O CN GHz-CHQ-CHS posure by blue light. The employment of such a coating in multi-layer color photographic materials is further illustrated in the accompanying drawing which shows in Fig. l a transparent cellulose acetate support i0 on which is coated a blue-red sensitive silver halide layer il containing dispersed therein a coupler which forms cyan dye. Coated on the blue-red sensitive emulsion layer il is a blue-green sensitive silver halide emulsion layer i2 containing dispersed therein a coupler which forms magenta dye` Coated on the blue-green sensitive layer l2 is a yellow filter layer` i3 containing a-[p-(-carboxypropionamido) benzoyll a di n propylaminobenzylidene)acetonitrile. Coated on the yellow iilter layer is a blue sensitive silver halide emulsion layer l containing dispersed therein a coupler which forms yellow dye. When such a photo graphic material was employed there was no noticeable loss in green or red speed in the blue* green blue-red sensitive emulsions. The blue-sensitive emulsion was affected only by elimination of blue light reflection from the under layers and support. rihe yellow iilter layer bleached completely in the normal processing; it was only necessary that a moderate concen tration oi sulte and alkali be present in one or more of the usual processing solutions. Typical multi-emulsion photographic materials in which our iilter dispersions can be employed are described in United States Patents 1,055,155,l dated March 4, 1913; 2,304,940, dated December l5, 1942, and 2,322,027, dated June 15, 1943, and 2,322,006, dated June 15, 1943.

were dissolved in cc. of methanol and 450 cc. of 1% aqueous sodium hydroxide solution. This dye solution was added at 40 C. to one pound of gelatin which had been previously dissolved in l0 lbs. oi water. The gel was then made up with water to a total weight of 30 lbs. Before coating as in Example l., the gel was adjusted with 2 N sulfuric acid to a pI-l of 5.0.

.Example 3 23 g. of a-(pcarboxymethylbenzoyl)-a-(pdiethylaminobenzylidene)acetonitrile having the formula:

OCN

CZHs

were dissolved in l5 cc. of pyridine and 650 cc. of ethanol. rlhis dye solution was added simultaneously with 25 g. of polyvinylpyridine methoptoluenesulfonate (which had been previously dissolved in 2 liters of water) to l0 lbs. of a 10% (by weight) dispersion of gelatin in water. The mixture was then set by chilling, shredded and washed. The washed gel was melted and made up to 30 lbs. weight with water. It can be employed es a lter as described in Example 1.

In the accompanying drawing, in Fig. 2, a transparent cellulose acetate support l5 is shown coated with a photographic silver halide emulsion layer 15 which is not dye-sensitized. The under side of the support is coated with a gelatin layer 17 containing a-(p-carboxymethylbenzoyl) a- (pdiethylaminobenzylidene) acetonitrile.

Example l4 To one pound of gelatin whichhad been dissolved in lbs. of water, there were added 200 cc. of a 10% (by weight) solution of Alkanol B (an alkylnaphthalene sodium sulfonate manufactured by E. I. du Pont de Nemours & Co.). `In a separate container, 17.5 g. of a-benzoyl-a-(pdiethylaminobenzylidene) -acetonitrile having the formula:

were dissolved in 500 cc. of di-n-butyl phthalate. This dye solution was added in a fine stream to l Example 5 To one pound of gelatin `which had been dissolved in 10 lbs. of water, there were added 100 cc. of a `10% (by weight) solution of Alkanol B (an alkylnaphthalene sodium sulfonate manufactured by E. I. du Pont de Nemours & 0o.). A solution of 32 g. of a-benzoyl--(p-diethylaminophenyl) ZA-pentadienoic nitrile having the formula:

O CN .02H5 -t|f- ]3=oH-crr=cnnn/ \o2H in 450 cc. of pyridine -wasaddedslowlyywith stirring, to the above gelatin solution. The resulting mixture was chilled until rigid, washed for 2 hours `with cold water to remove pyridine, remelted and made up to lbs. weight with water. The resulting dispersion when coated over an area of D sq. ft. will transmit not more than 1% of the incident light at 520 ma. Such a dye dispersion can be employed, for example, as an `antihalation layer for photographic materials comprising emulsions which are not dye-sensitized.

In a manner similar to that shown in the lfore-- going examples still other dyes of Formula IV `can be employed inpreparing photographic-mawrials containing lters, e. g. a-[p-lo-carboxybenzamidmbenzoyll `a (p-.diethylaminobenzylidene) acetonitrile, a- [p-(-carboxypropionamido) J benzoylla (p diethylaminobenzylidene) acetonit-rile, a- (p-diethylaminobenzylidene) .a (pippopionamidobenzoyl) acetonitrile, `e-lp- (li-carboxypropionamido) -benzoyll a (p-di-n-butylaminobenzylidene) acetonitrile, c- [p (-carboxyacrylamido)benzoylla(pdi -n butylaminobenzylidene) acetonitrile, a- (lp-di-n-propylaminobenzylidene) a (p-hydroxybenzoyl)iacetonitrile, a -(p diethyiarninobenzylidcne) a (33,1l-dihydroxyben- ZoyDacetonitrile, etc.

The dyes of Formula IV rabove can `be'prepared by condensing an aroylacetonitrile with a p-dialkylaminobenzaldehyde or a p-dialkylaminocinamaldehyde, in the presence of a secondary amine of the piperidine series, e. g. piperidine y Z-methylpiperidine, 3-methylpiperidine,etc. The dyes of Formula IV above wherein R3 represents an aryl group containing an acylamino group are advantageously prepared by condensing Van .ap-aminobenzoyua -p 1- dialkylaminobenzyli- Adene)acetociti-ile for `an `a-(p-aminobenr/.oyl).5- `(p-,dialkylaminophenyl)-2,1pentadienoic nitrile with anacyl chloride, in thepresence of a hetero- -1cyclic base of 'the pyridine series. The dyes `of Formula IV above wherein R3 `:epresents an aryl group containing `an alkylsulfonylamino group or .ian arylsulfonylamino group are advantageously prepared 1J-y condensing an la-(p-aminobenzoyl) .a-lp-dialkylaminobenzylidene)acetonitrile or an a- (peaminobenzoyl) (p-diallrylaminophenyl) .2,4-pentadienoic nitrile with an alkylsulfonyl chloride `oran arylsulionyl chloride, in the presence of a heterocyolic base of the pyridine series. The dyesfof `Formula IV above wherein R3 reprezsents an `aryl group `containing a. carboxyacylamino `group are advantageously prepared by `condensing an a- (p-aminobenzoyl) -a- (p-dialkyl- .amincibenzylidenelacetonitrile or an a-(p-aminobenzoyn pdialkylaminophenyl) 2,4 penta- 1dienoic-nitrile ywith a carboxylic anhydride, in the presence of a heterocycic base Aoi the pyridine series. Such dyes containing a carboxyacylamino group are `described `in the copending application of Grafton Keyes yand Leslie G. S. Brooker, Serial No. 117,709, filed of `even date herewith.

The following examples will serve to illustrate the manner ofpreparing various of the dyes ooming under Formula IV.

Example -6 .-a-benzo'yl-a- (p-dethylcminobenayudame) acetom'trz'le O C-N 02H5 4.8 g. (1 mol.) of benzoylaoetonitrile, 7.4 g. '(,1 moll-.25% excess) of p-diethylaminobenzalde- 'hyde, 30 cc. of absolute ethyl alcohol and 2 drops of piperidine `were reluxed together for a period of 4 hours. `Upon chilling the reaction mixture, the dye separated. It was ltered off and twice recrystallized from methylalcohol and obtained as reddish crystals with a blue reflex, melting at 89 to 93 C.

Ent-ample 7.--11-(lp-dicthylaminobenaylidene)-e- (3,4-dihydroybenzoyl) acetom'trile 1.8 g. (1 mol.) of 3,e-dihydroxybenzoylaceto nitrile, (Sonn, Ber. 51, 1829 (1918)), 1.75 g. (1 moli) of p-diethylaminobenzaldehyde, 30 ce. of absolute ethyl alcohol and 2 drops of piperidine were ,refluxed together for 3 hours. Upon addition of water Vto the cooled reaction mixture, the dye separated. `It was filtered oi and twice recrystallized `from methyl alcohol and obtained as amber crystals having a blue reflex and melting at 168 to 170 C. with decomposition.

3.5 g. (1 mol.) of a-(p-amincbenzeyl)-a-(pdi-n-propylaminobenzylidene)acetonitrile, 1.8 g. `(l mol.) of benzenesulionyl chloride and 15 cc. of `pyridine were heated at steam bath temperature for one hour. The dye was precipitated from the `reaction mixture upon adding water. The dye was filtered off and twice recrystallized from methyl alcohol. It was obtained as brownish- Ayellow crystals, melting at 204 to 205 C. with decomposition.

. :Using methanesulfonyl chloride or ethanesulfonyl chloride, a-(p-di-n-propylaminobenzylidene) a (p-methylsulfonamidobenzoyl) acetonitrile and a-(p-din-propylaminobenzylidene) -a- (pethylsulfonamidobenzoyl)acetonitrile can be similarly prepared. I

The a (p aminobenzoyl) a (pdinpropyl aminobenzylidene)acetonitrile employed in the above Example 8 can be prepared as follows:

8 g. (1 mol.) of paminobenzoylacetonitrile, 10.25 g. (1 mol.) of p-di-n-propylaminobenzaldehyde, 100 cc. of absolute ethyl alcohol and 4 drops of piperidine were reuXed together for a period of three hours. Upon chilling the reaction mixture, the dye separated. The dye was purified by two recrystallizations from methyl alcohol and obtained as brownish-orange crystais, melting at 148 to 150 C. with decomposition. Using pdiethylaminocinnamaldehyde, a (aminobenzoyl) (p diethylaminophenyl) 2,4-pentadienoic nitrile can be prepared in a similar manner.

Eampe 9.-1-(p-diethyl'aminobeneylidene) -a-` (p-popz'onamidobeneoyl) acetom'trile 3.2 g. (1 mol.) of a-(p-aminobenzoyD-a-(pdiethylaminobenzylidene)acetonitrile, 1.4 g. (l mol.+50% excess) propionyl chloride and 15 cc. of pyridine were heated for l5 minutes at steam bath temperature. 'he dye was precipitated on addition of water to the cooled reaction mixture. It was filtered oi and purified oy two recrystallizations from methyl alcohol. It was obtained as bright orange crystals, melting at 186 to 188 C. with decomposition.

Using acetyl chloride or isobutyryl chloride, ap-diethylaminobenzylidene) a (p-acetamidobenzoyDacetonitrile and a (p diethylaminobenaylidene) a-(p-isobutryramidobenzoyl) acetonitrile can be similarly prepared.

The a. (p-aininobenzoyl)-a-(p-diethylaminobenzylidenwacetonitrile employed in the above Example 9 can be prepared as follows:

1.6 g. (l mol.) of paminobenzoylacetonitrile,

1.75 g. (1 mol.) of p-diethylaniinobenzaldehyde and 2.. cc. of ethyl alcohol were heated under a reiiuny condenser. Two drops of piperidine were add to the mixture which was then reluxed fo" Ae hours. The dye separated on chilling th eaction mixture. 1t was filtered oi and twice re vstallized from methyl alcohol and obtained f orange-brown crystals, melting at 144 to 147 C. with decomposition. Y

Example Z 0.-a (p-Carboymethylbeneoy -av- (pdiethylumznobeneylidene) -ccetonitrile (Kunckell, Ber. 41, 3046 (1908)) were dissolved in 50 cc. of ethyl alcohol and to this solution was added a solution of 12 g. (5 mol.) of potassium cyanide in 25 cc. of water; the resulting mixture was heated at steam bath temperature for 30 minutes. It was then chilled, made acid with hydrochloric acid and the p-cyanophenylacetic acid precipitated by adding 300 cc. of water. rlhe precipitated product was ltered ofi, Washed and dried.

1.45 g. (i mol.) of benzoylacetonitrile, 2 g. (1 mol.) of p-diethylaminocinnamaldehyde, 50 ce. of absolute ethyl alcohol and 2 drops of piperidine were reuxed together for 11/2 hours. Upon chilling the reaction mixture, the dye separated. After two recrystallizations 'from methyl alcohol the dye was obtained as dull blue crystals, `-.e1ting at 110 to 112 C.

Eaiample 12.-a-[p (,8 Carboypropionamido) benzoyll a-(p-oli-n-propyldminohef/Leylidene) ctcetom'trile 3.5 g. (1 mol.) of a-(p-aminobenzoyl)a-(p-di n-propylaminobenzylidene)acetonitrile, 1.5 g. (1.5 mol.) of succinic anhydride and 15 cc. pyridine were heated for a one-hour eriod at steam bath temperature. The re ction mixture was then poured into about 200 cc. of cold water. The reaction mixture was made acidic with hydrochloric acid, whereupon the dye separated.. It was filtered off and twice recrystallized from methyl alcohol and obtained as orange melting at 184 to 186 C. with decomposition.

Typical photographic developers in wl 'cdyes oi our invention are bleached inns-de example Eastman Kodak Companys TD-78 developer which has the following composition:

N-methyl-p-aminophenol sulfate lbs 2 Sodium suliite, desiccated lbs 100 Hydroquinone lbs 5 Borax lbs 2 Water to make gal 120 and the photographic developers disclosed in United States 2,113,329, dated April 5,

Our filter dispersions can be employed in con junction with any of the lifghtnsensitive photo- `graphic silver halide emulsions, e. g. the gelatino-silver-bromoiodide, gelatine-silver-bromide, gelatino-silver-chlorobromide, gelatine silverchloride, gelatine-silver-chioroiodide, etc. The supports upon which such emulsions can be coated or otherwise positioned can be any of the usual supports, e. g. glass, cellulose acetate film, cellulose nitrate film, polyvinyl acetal resin film, nylon resin film, etc.

Where the dialkylaminobenzylidene dyes employed in our invention contain acid saltforming groups, e. g. phenolic hydroxyl groups, carboxyl Vcan Vbe formed.

prepared by dissolving the acid dyes in ethyl aleohol containing ammonia, methyla' d ethylamine,Y triethylamine, ethanolamine, ethyleis-sacos enediamine, pyridine, piperidine, N-methylpiperidi neto Poly-vinyl pyridine metho-p-toluenesulfonate can be prepared by heating polyvinyl pyridine i-vinylpyridine polymer) with methyl p-toluenesulionate, in nitr-obenzene, at about 190" C. for about 3U minutes, as described in thecopending application of Robert H. Sprague and Leslie G. S. Brooker, Serial No. 719,624 (now United States Patent No. 2,484,430, dated October 11,

O l i i i Ho--eHT-CHZ-c-N-@cqlhorGrR 1949) filed December 31, 1946.

p-Amincbenzoylacetonitrile can be prepared as follows: g. of p-chloroacetylaniline (Kunckell, Ber, 33, 2644 (1900)) were dissolved in 100 cc. oi methyl alcohol. To this solution were added 19 g. oi potassium cyanide dissolved in 50 cc. of water. A vigorous reaction took place. The reaction mixture was acidified with acetic acid, whereupon p-aminobenzoylacetonitrile separated out. lt was filtered off and washed with Water. Upon recrystallization from water, the compound was obtained as colorless crystals melting at i500 C.

What .ve claim as our invention and desire to be secured by Letters Patent of the United States 1s:

1. A light-sensitive photographic material containing a silver halide emulsion and a lter comprising a dispersion in a water permeable colloid or at least one dialkylaminobenzylidene dye seleeted from those represented by the following general formula:

o CN

wherein D represents a p-arylene group of the benzene series, n represents a positive integer of from l to 2, R1 and R2 each represents an alkyl group, and Re represents an aryl group of the benzene series, and the salt forms of such dyes which contain an acid salt-forming group.

2. A light-sensitive photographic material containing a silver halide emulsion and a lter comprising a dispersion in a water permeable colloid of at least one dialkylaminobenzylidene dye selected from those represented by the following general formula:

o GN

wherein R3 represents an aryl group of the benzene series containing in addition to carbon atoms no atoms other than hydrogen atoms, oxygen atoms, sulfonamido sulfur atoms, sulfonamido nitrogen atoms and carboxamide nitrogen atoms, and R1 and R2 each represents a primary alkyl group of the formula Cnil-12min wherein m represents a positive integer of from 1 to 4, and the salt i'orms of such dyes which contain an acid saltforming group.

3. A light-sensitive photographic material containing a silver halide emulsion and a filter comprising a dispersion in a water permeable colloid ci at least one diallylaminobenzylidene dye selected from those represented by the following general formula:

wherein R1 and R2 each represents a primary alkyl group of the formula CmlI2m+1 wherein m represents a positive integer of from 1 to 4, and the salt forms of such dyes.

4. A light-sensitive photographic material containing a silver halide emulsion and a lter comprising a dispersion in a water permeable colloid of at least one member selected from the group consisting of the diallcylaminobenzylidene dye represented by the following formula:

CH2`CH2CH3 and thesaflt forms of such dyes.

5. A light-sensitive photographic material containing a silver halide emulsion and a lter comprising a dispersion in a water permeable colloid of at least one dialkylamin-obenzylidene dye selected from those represented by the following general formula:

0 CN Rr Ho o c-CH2--tL-tli=on-C N/ wherein R1 and R2 each represents a primary alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 4, and the salt forms of such dyes.

6. A light-sensitive photographic material containing' a silver halide emulsion and a filter comprising a dispersion in a water permeable colloid of at least one member selected from the group consisting of the dialkylaminobenzylidene dye represented by the following formula:

and the salt forms of such dye.

'7. A light-sensitive photographic material containing a silver halide emulsion and a iilter comprising a dispersion in a water permeable colloid of at least one dialkylaminobenzylidene dye selected from those represented by the following general form-ula:

wherein R1 and R2 each represents a primary alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from l to "l, and the salt forms of such dyes.

8. A light-sensitive photographic material containing a silver halide emulsion and a lter comprising a dispersion in a water permeable colloid of at least one member selected from the group consisting of the dialkylarninobenzylidene dye represented by the following formula:

o CN

and the salt forms of such dye.

9. A light-sensitive photographic material comprising a support upon one side of which is positioned a silver halide emulsion layer which is not dye-sensitized, the opposite side of the support having an antihalation layer comprising a dispersion in a Water permeable colloid of at least one dialkylaminobenzylidene dye selected from those represented by the following genere-l REFERENCES CITED ffmula The following references are of record in the 1) (EN /Rl fue of this patent: mAh-0:05(-CH=CH) 1-DN\ 5 UNITED STATES PATENTS R2 Number Name Date wherein D represents a, p-arylene group of the 2,036,545 Schneider Apr. 7J 1936 benzene series, n represents a. positive integer of 2,078,393 Mannes et Q1- Apr 27, 1937 from 1 to 2, R1 and R2 each represents an alkyl 2,255,077 Middleton Sept. 7, 1941 group, and R3 represents an aryl group of the 10 benzene series, and the salt forms of such dyes which contain an acid salt forming group. GRAFTON H. KEYES. ARTHUR H. HERZ. LESLIE G. S. BROOKER. l5 

1. A LIGHT-SENSITIVE PHOTOGRAPHIC MATERIAL CONTAINING A SILVER HALIDE EMULSION AND A FILTER COMPRISING A DISPERSION IN A WATER PERMEABLE COLLOID OF AT LEAST ONE DIALKYLAMINOBENZYLIDENE DYE SELECTED FROM THOSE REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 